<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>取消请求</title>
</head>

<body>
    <button>发送请求</button>
    <button>取消请求</button>
</body>
<script>
    const btn = document.querySelectorAll('button');
    let x = null;
    btn[0].onclick = function() {
        x = new XMLHttpRequest();
        x.open('GET', 'http://127.0.0.1:8000/delay');
        x.send();
    }
    btn[1].onclick = function() {
        x.abort();
    }
</script>

</html>